Regulator



p 1942- v R. A. GEISELMAN 2,295,397 I REGULATOR Filed April 5, 1941Sheets-Sheet 1 WITNESSES: INVENTOR 5 4 Babb/766456407071.

BY I V 7 gg aiyy Ea/pb flee/sewed P 9 RA. GEISELMAN 2,295,397

' REGULATQR 'Filed April 5, 1941 2 SheetsSheet 2 wnmassssi INVENTORPatented Sept. 8, 1942 REGULATOR i ins Pa, assign to WestinghouseElectric & MLuhctm-lng or Com-- pany, East Pittsburgh, Pa, a corporationof Pennsylvania Application April 5, 1941, Serial No. 387,044

Claims; This invention relates to regulators, and particularly toregulators and regulating systems employed in controlling the speed ofdynamo electric machines.

An object of this invention is to utilize an electromagnetic devicemovable in response to change in speed of a dynamo-electric machine forinitiating the control 01 the excitation of the machine and to providefor a damping operation to prevent excessive changes in the excitation.

Other objects oi! this invention will become apparent from the followingdescription when taken in conjunction with the accompanying drawings, inwhich: i

Figure l is a diagrammatic illustration of circuits and apparatusembodying this invention, and

Fig. 2 is a perspective view with parts broken away of theelectromagnetic device utilized ina diagrammatic illustration of Fig. 1.

Referring to Fig. 1, there is illustrated a constant speed referencemachine, such as the motor Ill, and a, dynamo-electric machine such 'asthe motor I2, the speed of which it is desired to regulate. The motorsl0 and 12 comprise an armature winding i4 and a field winding I6, and anarmature winding i 8 and field winding 20, respectively, the armaturewinding of the respective motors being connected to any suitable Thefield wind- 1 source of power (not shown). ing I6 01' the constant speedmotor I! is also connected to a constant source oi power (not shown).

The motors l0 and I2 are connected .through a synchronous drive in awell-known manner, a synchronous transmitter 22 and a synchronousreceiver 24 being associated with the motor l0,

and a synchronous transmitter 26 and a synchronous'receiver 28 beingassociated with the motor l2. The synchronous transmitters andsynchronous receivers associated with the motors Iii and I2 areduplicate wound rotor induction motors having their primaries connectedthrough conductors 29 to a constant three-phase alternating currentsupply source (not shown), with the rotors oi the associatedtransmitters and receivers being electrically connected together byconductors OIL- The transmitters and associated receivers function inthe well-known manner, so that when properly connected or phased out,the machines remain stationary and there is no current the rotorcircuits. However, when the transmitter is turned, the small phasedisplacement between it and'th e receiver causes a current to fiowbetweenthemachines developing a torque or turning moment. Asillustrated, the rotors oithe'transmitters 22' and 26 are mechanicallyconnected to and disposed to be driven-by the motors II and II,respectively.

The rotor of the receiver 24 is connected to drive one side of amechanical differential connection I2, the rotor of the receivermechanically connected to drive the other side of the diiiierentialconnection. The diii'erential connection comprises end or sun gearwheels 34 and it which are, respectively, driven by the re-' I ceivers24 and 2! and a middle or' planetary gear wheel 38 which is responsiveto the diri'erential speeds of the end gear wheels.

The field windfiag 20 of the dynamo-electric, machine 12 is connected tobe energized from a cpnstant source of direct current power, representedby the conductors 40 and 42. As illustrated, one end of the fieldwinding '20 is connected directly to the conductor 40, the other end 01'the field winding 20 being connected through a variable resistor 44,conductor 45, the primary winding 48 of a current transformer 50,conductor i2, the atrmature winding. 54 of an exciter generator 56 andconductor 58 to the line conductor 42. The exciter generator 56 has afield winding 60 and is 01' the buck-boost type for controlling theexcitation of the field winding 20.

A Wheatstone bridge resistor 62 having two variable resistor legs 64 and66 and two constant resistor legs and 61 is connected in circuitrelation with the field winding 60 of the generator 56 by conductors 68and 10 extending from twoof the terminals of the resistor bridge. Theterminal of the bridge 62 between the legs 65 and 61 is connected toline conductor 40 through a variable resistor 12, and the terminalbetween the variable resistor legs 64 and 66 is connected to the lineconductor 42 through a manual operable switch 14.

Primary control devices 16 and 18 are associated and electricallyconnected to the terminals or taps of the variable resistor legs 64 and66, respectively, of the bridge 62 for controlling the shunting of thesections of the resistor in each leg, thereby controlling the directionof flow 01' current in the field winding 60 of generator 56, and alsocontrolling the degree of excitation of the field winding 60. Each ofthe primary devices l6 and 18 comprises a plurality of elongated,self-biased conducting leaf springs having one end secured in fixedrelation and insulated from each other by a suitable insulating holdingmechanism 82, the other ends of the spring leaves 80 carrying contactmembers 84 and being disposed to be actuated in sequence away from asloped stop 86 to progressively contact the contact members; The fixedends of the spring leaves 80 are connected by conductors 88 to terminalson the variable resistor 64 or 66 associated with the primary controldevice 18 or 18, respectively. Further description of the primarycontrol devices 16 and I8 is believed to be unnecessary in describingthis invention, but may be had by reference to the copending applica- 28being tion Serial No. 203,876 of C. R. Hanna et al.,

now Patent 2,246,301, June 1'7, 1941, and as-,

signed to the assignee of this invention.

An electromagnetic device 80 is provided as the primary actuating meansfor actuating the conducting members 80 of the primary control devicesI8 and I8 to control the-excitation of the generator 66 in accordancewith predetermined gear wheel 38 moves in response to the difierentialspeeds of the end gear wheels 34 and 33 of the differential connection32.

Referring. to Fig. 2 of the drawings, there is illustrated theelectromagnetic device 90 comprising the actuating means for the contactmembers of the primary control devices I6 and I8 in accordance with thisinvention. As illustrated, the electromagnetic device 90 comprises asubstantially U-shaped core member 9 I, an energizing winding 84 carriedon the core member 9I and an armature 96 disposed to be actuated inaccordance with the energization of the winding 84. A sideplate 98 ofnon-magnetic material is mounted on the core member 9| as by means ofscrews I and is provided with a depending portion I02 having a slot I04therein for receiving the end of the shaft 92 driven by the planetarygear wheel 38 of the differential device 32. The shaft 92 ismechanically retained in the slot I04 by means of tightening the screw I06, the edges of the slot thereby gripping the end of shaft 92. Asillustrated, the shaft 82 projects through a supporting bearing I08which is carried in a panel (not shown) The armature 96 is carried on alever arm IIO and disposed to be integrally mounted on the core member9I of the electromagnetic device 90. As illustrated, a substantially'U-shaped bracket member II2 of non-magnetic material is mounted on thetop edge of the core member 9| as by means of non-magnetic screws II4,the U-shaped bracket member having upwardly turned ends The lever IIOalso carries the bracket member II8 which extends beyond the sides ofthe lever IIO. As illustrated, a pivot for the lever H0 and the armature96 carried thereby is provided by a plurality of horizontal spring leafmembers I20 secured to and extending. between the ends of the upwardlyprojecting portion II6 of the U-shaped bracket H2 and the ends of thebracket II8 on each side of the lever member IIO. A plurality ofvertical spring leaf members I22 disposed on each side of the levermember H0 is secured to and extends between the edges of the bracket, II8 and the bracket H2, The combination of the vertical and horizontalspring members I22 and I20 gives a substantially floating pivotalmounting for the lever IIO, the spring members, however, being soconstructed that they are relatively weak for permitting slightmovements of the armature 96, and consequently the lever IIO, but arerelatively stifi for resisting and preventing large movements of thelever H0 and armature 96 carried thereby. As in standard practice, aspring member I24 is connected between the lever I I0 and an adjustablescrew I26 which is carried in a bracket I29 of non-magnetic materialsecured to the core member 9I by non-magnetic screws I29 for balancingthe pull on the armature 96. The lever IIO also carries driving membersI30 and I32 of non-conducting material dis- II8 for facilitating themounting of the lever IIO.

posed for actuating the spring leaf members of primary control devices16 and 18, respectively. The primary control devices are mounted on asuitable panel (not shown) in position whereby a movement of the leverarm IIO actuates the driving members I30 or I32 to engage the conductingmembers of one or the other of the primary control devices dependingupon the direction of movement of the lever. 1

Referring to Fig. 1, the electromagnetic device carried by the shaft 92has its energizing windin 94 connected to the constant source of directcurrent represented by the conductors 40 and 42, one end of theenergizingwinding being connected by conductor I34 to line conductor 42,the other end of the winding 94 being connected through the secondarywinding I36 of a potential transformer I38 and the secondary winding 49of the current transformer 60 tothe line conductor 40. The primarywinding I31 of the potential transformer I38 is connected across thearmature 54 of the generator 56, the purpose of which will be explainedmore fully hereinafter.

In operation, assuming that the switch I4 is manually operated to closethe circuit from the conductors 40 and 42 through the energizing winding60 of the exciter generator 56, and assuming that the motor I2 isoperating at the desired speed with respect to the constant speedreference machine I0, then no movement of the electromagnetic device 90is obtained to actuate the conducting members 80 of the primary controldevice I6 or I8 and since the bridge 62 is balanced, current will notflow in the winding 60 of the generator 66. The field winding 20 of themotor I2 is consequently energized directly from the constant source ofdirect-current represented by the conductors 40 and 42.

If for any reason the speed of the motor I2 increases with respect tothe speed of the constant speed reference machine I0, the transmitter 26is operated to effect a phase displacement between the transmitter 26and the receiver 28. Consequently, a torque or turning moment isdeveloped for actuating the differential device 32 to effect a movementof the planetary gear wheel 38 of the differential device.

Assuming that the torque effects a gnovemen of the shaft 92 to drive theelectromagnetic device 90 toward the left, as viewed in Fig. l, thedriving member I30 carried by the lever IIO engages the conductingmembers 80 and progressively and in sequence forces them away from thesloped stop 86 to shunt successive sections of the variable resistor 64.

The shunting of the sections of resistor 64 causes a current to flow inthe circuit which may be traced from line conductor 42, through theswitch I4, the first conductor 88, the closed contact members 84 of theprimary control device I6, the last conductor 88 of the closed conductorsprings 80, the sections of the leg 64 of the bridge 62 which are notshunted, conductor I0, winding 80 of the generator 56, conductor 68, leg61 of the bridge 62 and the variable resistor 12 to the line conductor40. The flow of current in the winding 60 of generator 56 energizes. thegenerator 66 whereby current of the sarne polarity as the current whichnormally flows through the field winding 20 connected to the conductors40 and 42 assess? the winding l4 of the electromagnetic device II ischanged to damp the initial -movement of the driving member Ill againstthe conducting members II. The energization of the generator IIincreases the voltage drop across. the armature windings 54 so that theflux induced in the secondary winding Ill of potential transformer I38causes a flow of current in the winding II to oppose the normal flow ofcurrent therein, thereby effecting a resultant decrease intheenergizstion of the winding 04 and permitting the springv I24 to effecta movement of the lever H about its pivotal mounting away from theconducting members ll. At substantially the same time the potentialtransformer functions to oppose the normal flow of current in thewinding 94 of electromagnetic device 94, the current transformer due tothe increase in flow of current through the primary winding 48 induces aflux in the secondary winding 4| thereof which also opposes the normalflow of current in the winding 94. combined effect of the potentialtransformer I" and the current transformer ll effectively functions todamp the movement of the electromagnetic device 90 initiated by amovement of the planetary gear wheel 3' of the differential device 32,and prevents the shunting of too many sections of the variable resistor64 from circuit with the field winding 80 of generator 86, therebypreventing too great a change in the exciting current, and consequentlyangoverregulation of the speed of the motor l2,

If for any reason the speed of the motor l2 decreases with respect tothe speed of the constant speed reference machine ll, then thedifferential device 32 functions through the planetary gear wheel 38 todrive the electromagnetic device SI towards the right, as viewed in Fig.l, to actuate the conducting spring leaf members 80 at primary controldevice 18 to shunt progressive sections of the variable resistor l6, andthereby effect a flow of current in the winding ll of generator 68 ofoppositepolarity than that effected by an operation of the primarycontrol device It to shunt the sections of resistor 64. With all of thesections oi the variable resistor N in circuit in the bridge 2 and withsections of the variable resistor 66 shunted, current flows from theconductor 42, through the manually operated switch 14, the firstconductor 88,, the closed contact members 84 of primary control deviceII, the last conductor 88 of the closed conductor springs 80, thesections of the resistor leg 88 which are not shunted, resistor 66,conductor 68, field winding 6. of the generator '56, conductor II,resistor 65 of the bridge 62 and the variable resistor 12 to -conductor40. The flow of current through the winding 80 being of oppositepolarity effects a bucking operation of the generator 56 to oppose thenormal flow of current from conductor 42, throughthe.

field winding 20 of motor I! to the conductor 40, thereby decreasing theenergization of the field winding 20, and consequentlyincreasing thespeed of the motor [2.

Simultaneously with thedecrease in the energization of the field winding20, the potential transformer I38 and the current transformer functionto induce a current in the energizing winding 94 which will boost thenormal current flow from conductor 42 through the winding 94 toconductor 40. The slight increase in the energization of the winding 94increases the magnetic pull on the armature". to actuate the lever armllll about its pivotal mounting in e, direc- The tromagnetic device 04in response'to movement of the planetary gear wheel 38 of thedifferential connection 32. This movement of the lever arm H0 about itspivotal mounting in opposition to the actuating movement of theelectromagnetic device It prevents the initiating movement of theelectromagnetic device I from overregulating the flow of current in thewinding of the generator i6 and consequently from overregulating theenergization' of the ,iield winding 2| of motor If. It is, of course, tobe understood that the current flow in the winding 84 of theelectromagnetic device Sl caused by the change in the energizatlon ofthe generator 7", through the damping transformers I and II is a smallchange and dies out as the current flow through the primary winding "ofcurrent transformer II and the voltage across the armature windings 54of the generator I become substantially constant. e

By providing the spring pivotal mounting for the lever H0, it is quiteevident that the small change in the current flowing in the magneticwinding 94 due to a change in the energization of the generator 56effects a slight movement of the lever H0 about its pivotal mounting.However, since the pivot spring members are relatively stiff. themovement of the planetary gear wheel a of the differential device 32 iseffectively transmitted through the pivotal mounting to effect a directmovement of the lever H0, and consequently the driving members carriedthereby to directly operate the primary control device I! or 78.

Whether the change in the energization of the field winding 20 of motorI! is an increase or a decrease, after the regulating action has beeninitiated and the desired increase or decrease in the energization isobtained, the generator 56 functions to permit the delivery of asubstaniii pended claims.

. tion opposing the initial movement of the electially constant currentfrom line conductor 42,

I through the field winding 20 to the conductor 4..

Under these conditions, the differential connection 32 and theelectromagnetic device carried thereby is stationary, no change in theenergization of the winding 94 of the electromagnetic device 90 beingencountered.

The regulator of this invention gives a direct, quick, accurateregulation while at the same time providing damping for preventingoverregulation of the exciting current. The apparatus employed is ofstandard design and can readily be assembled in the simplifiedarrangement of parts illustrated and described for obtaining the quickaccurate control.

Although this invention has been described with reference to aparticular embodiment thereof, it

is, of course, not to be limited thereto except in-- sofar as isnecessitated by the scope of the ap- I claim as my invention:

1. In a regulator, in combination, a constant speed reference machine, adynamo-electric machine provided with a field winding to be regulated, adifferential connection disposed between the constant speed referencemachine and the dynamo-electric machine, the differential connectionbeing responsive to changes in speed between the reference machine andthe dynamoelectric machine, means for exciting the fleld winding of thedynamo-electric machine, means for controlling the current delivered bythe exciting means, an electromagnetic means comprising a core member,an energizing winding carried by the core member and an armaturepivotally carried by the core member, the electromagnetic means beingcarried by the differential and being so disposed that when it is movedby the differential it actuates the means for controlling the excitingcurrent, the energizing winding of the electromagnetic means beingresponsive to a. function of the exciting current for operating thecontrol means for the exciting current thereby effecting a damping ofthe operation initiated by the movement of the differential.

2. In a regulator, in combination, a constant speed reference machine, adynamo electric machine provided with a field winding to be regulated, adifferential connection disposed between the constant speed referencemachine and the dynamo-electric machine, the differential connectionbeing responsive to changes in speed between the constant speedreference machine and the dynamo-electric machine, means for excitingthe field winding of the dynamo-electric machine, a plurality of contactmembers disposed to be actuated into engagement in sequence forcontrolling the current delivered by the exciting means, anelectromagnetic means comprising a core member, an energizing windingcarried by the core member, an armature pivotally carried by the coremember, and a driving member carried by the armature, the driving memberbeing disposed for movement as the armature moves to actuate the contactmembers, the electromagnetic means being carried by the differential,the electromagnetic means being so disposed that when it is moved by thedifferential the driving member actuates the contact members forcontrolling the exciting current, the energizing winding of theelectromagnetic means being responsive to a function of the excitingcurrent for actuating the driving member in opposition to the movementof the electromagnetic means initiated through a movement of thedifferential to damp the initial controlling operation.

3. In a regulator, in combination, a constant speed reference machine, adynamo-electric machine provided with a field winding to be regulated, adifferential con'iection disposed between the constant speed referencemachine and the dynamo-electric machine, the differential connectionbeing responsive to changes in speed between the reference machine andthe'dynamoelectric machine, means for exciting the field winding of thedynamo-electric machine, means for controlling the current delivered bythe ex citing means, an electromagnetic means comprising a core member,an energizinz winding carried by the core member and an armaturepivotally mounted on the core member, the pivotal mounting for thearmature permitting a slight movement of the armature but beingrelatively stiff to resist a large movement of the armature, theelectromagnetic means being carried by the differential, theelectromagnetic means being so disposed that when it is moved by thedifferential it actuates the means for controlling the exciting current,the energizing winding of the electromagnetic means being responsive toa function of the exciting current for effecting aslight movement of thearmature about its pivotal mounting for operating the control means forthe exciting current whereby the operation initiated through a movementof the differential is damped by the electromagnetic means.

4. In a regulator. in combination. a constant speed reference machine, adynamo-electric machine provided with a field winding to be regulated, adifferential connection disposed between the constant speed referencemachine and the dynamo-electric machine, the differential connectionbeing responsive to changes in speed between the constant speedreference machine and the dynamo-electric machine, means for excitingthe field winding of the dynamo-electric machine, a plurality of contactmembers disposed to be actuated into engagement in sequence forcontrolling the current delivered by the exciting means, anelectromagnetic means comprising a core member, an energizing windingcarried by the core member, an armature pivotally mounted on the coremember, and a driving member carried by the armature, the pivotalmounting for the armature being relatively weak to permit a slightmovement of the armature and relatively stiif to resist a large movementof the armature, the driving member being disposed for movement as thearmature moves to actuate the contact members, the electromagnetic meansbeing carried by the differential, the electromagnetic means being sodisposed that when it is moved by the differential the movement istransmitted by the relatively stiff pivotal mo'unting-to the drivingmember to actuate the contact members for controlling the excitingcurrent, the energizing winding of the electromagnetic means beingresponsive to a function of the exciting current for effecting a slightmovement of the armature about its pivotal mounting to actuate thedriving member in opposition to the movement of the electromagneticmeans initiated through a movement of the differential to damp theinitial controlling operation.

5. In a regulator, in combination, a constant speed reference machine, adynamo-electric machine provided with a field winding to be regulated, adifferential connection disposed between the constant speed referencemachine and the dynamo-electric machine, the differential connectionbeing responsive to changes in speed'between the constant speedreference machine and the dynamo-electric machine, a generator .providedwith a field winding for exciting the field winding of thedynamo-electric machine, a resistance bridge having two variableresistor legs connected in circuit with the field winding of thegenerator, a primary control device comprising a plurality of contactmembers disposed to be actuated in sequence associated with each ofthevariable resistor legs for adjusting the resistance of the bridge andcontrol the excitation of the generator, thereby controlling theexcitation of the dynamo-electric machine, electromagnetic means carriedby the differential, the electromagnetic means comprising a core member,an energizing winding carried by the core member and an armaturepivotally carried by the core member, the electromagnetic means beingdisposed for movement when the differential is moved to actuate thecontact members in sequence, the energizing winding of theelectromagnetic means being responsive to a change in the excitation ofthe field winding of the dynamoelectric machine to effect a damping ofthe op, eration initiated by the movement of the differential.

RALPH A. GEISELMAN.

